I was crawling under my XJ yesterday for another issue and noticed an area where the floor panel has rusted through. How big of an ordeal is it to cut that area out and weld in a new section? I don't have any other major rust, and the Jeep is mechanically sound, but I don't want the rot to get worse next winter.

The hole is about an inch wide on the driver's side floor between the rocker and the frame rail.

 

"I don't have any other major rust"

that's what I thought too, wait until you lift your carpet and it all goes downhill from there. I thought the same, then the infamous "oh what's this? let me use a screwdriver to see if it's solid *go through the floor* well alright I guess while I'm at it I might do thi... *even bigger hole appears* ... well f*ck!..."

let's say you truly have one hole, yes it's pretty simple to just cut around it, get some sheet metal and with access to a welder patch it relatively quickly. the issue is how many other holes will you find while you're at it.

 

I have to agree, I thought I only had a couple holes looking from underneath...


This is what I cut out, just replaced both floor pans and was done with it.
I hope you truly have just on small hole, but tis not the end of the world if its more, just a little more time consuming.